A Text To Speech (TTS) system is a device for translating text to audio signals. Due to the fast development of the semiconductor industry, these systems are today entering the consumer electronics market. In particular, these systems are today being implemented in Personal Computers (PCs), Personal Digital Assistants (PDAs), Mobile Phones (MPs) and Car Accessories (CAs).
One of the most desirable applications for a TTS system is in car hands-free equipment for mobile telephones. Today, mobile phones have the possibility of receiving so-called SMS (short message service) text messages. Through these SMS messages, text can be transmitted to a specific mobile subscriber. The messages can be created and edited, for example, in another mobile telephone or in an e-mail editor at a PC. SMS messages can also be used for transmission of traffic information and other news and data.
SMS messages are normally represented in a display of the mobile telephone and the user has to read them from there. However, there are many situations where reading the display can be difficult and even dangerous. In a car hands-free situation, for example, the driver may not be able to read the display contents since he/she has to concentrate on the road. For this reason, there are now law restrictions on using mobile phones while driving. Text to speech conversion is a good solution to overcoming the restriction. The TTS reads the text for the user through the loudspeaker.
However, a problem with currently available systems is that they normally support only one language. In some more advanced equipment, the user must choose manually the language to use by the TTS system. However, since different languages have different pronunciations of the alphabet, a message in one language can be unintelligible if spoken by a system designed for another language.
It will be readily appreciated that similar comments apply to text received in the form of e-mails, WAP (Wireless Application Protocol) pages or other text systems, in addition to SMS messages.